Me autorespondo ... encontre esta explicacion en un foro del Note 2
PROBLEMAS CON LA SALIDA HDMI: Debido a que usa drivers propietarios, la salida de HDMI nunca va funcionar en roms AOSP.
Otro comentario de una Omnirom para Note7000 y lo mismo
first impressions
after only few days testing Omnirom on my samsung note I can say:
1) with this rom the phone is incredible fast and responsive
2) MHL cable (Hdmi) is not working
3) battery drain is the biggest issue
4) I'd like to have support for USB asynchronous transfer mode because I need to connect external USB audio devices